Analysis And Optimization Of Flat Car Body Structure

With the continuous advancement of industrialization in China,railways have become an important support for the national economy.Due to the increase in domestic freight demand,railway freight will develop towards high-speed,heavy-duty,and lightweight directions,which also poses new challenges to the safety of truck operation.The lightweight design of trucks can not only reduce the consumption of raw materials,improve the speed of cargo transportation,but also reduce transportation costs to a certain extent.However,blindly reducing the weight of the vehicle body can damage the structure of the vehicle body and affect its operational safety.Therefore,it is particularly important to use reasonable methods to conduct lightweight research on the vehicle body.This article takes the flat car body as the research object,and analyzes and optimizes the car body based on finite element and structural optimization methods.The work content of this article is as follows:Firstly,understand the development status and research history of flat car and structure optimization at home and abroad,summarize the relevant knowledge involved in finite element analysis and optimization design of flat car,and determine the finite element analysis route and structure optimization process of flat car body.Based on the relevant knowledge,the flat car body structure is analyzed and the body model is meshed by the finite element analysis method.Secondly,the flat car body is restrained according to the relevant regulations in TB/T3550-2019,and the static strength and stiffness of the flat car body are determined according to the body load values and load application methods specified in the standard.The stiffness,static strength,mode and structural stability of the flat car body are evaluated.The fatigue life of the welds on the flat car body was evaluated with reference to AAR standard MSRP-C-II 2015.Then,the topological optimization design of the body is carried out according to the results of finite element analysis.Three topological optimization schemes are proposed for flat car body,and then the stiffness and static strength of the optimized body are verified to determine the feasibility of the three optimization schemes,and the topological optimization results of different schemes are compared and analyzed.Finally,scheme 1 with better weight reduction effect and clearer material distribution is selected as the final optimization scheme,i.e.topological optimization design of the body is carried out with minimum flexibility as the objective function in order to find the best material distribution of the body.Remove excess material from the body according to the optimization results,and carry out polygonal trimming of irregular holes formed after material removal.On this basis,carry out secondary modeling of the body.Finally,on the basis of topology optimization and taking the minimum quality as the objective function,the appropriate design variables are selected based on sensitivity analysis to optimize the dimensions of the body.Adjust the body parameters according to the optimization results and check the mechanical properties of the optimized body.The results show that the performance of the optimized flat car body still meets the requirements,and the weight of the vehicle is reduced by 9.2% compared with that before optimization,thus realizing the lightweight of the flat car body.